1. Field of the Invention
The present invention relates to exercise equipment. More particularly, exercise equipment of the type that a person can stand upon and work his or her lower body by engaging his or her feet with a pair of upwardly spring-biased treads.
2. Description of the Related Art
Exercise equipment is known that, to varying extents, satisfy important countervailing requirements. The most important requirements are (1) it must safely and effectively work at least one of the major muscle groups, isolated muscles, or the cardiovascular system, and (2) it must be fun and enjoyable. Exercise equipment that cannot satisfy these two basic requirements, while at the same time tertiary goals of being sturdy, reliable, convenient, inexpensive, and simple to use, will not be successful. For example, free weights achieve many of these goals, but without additional specialized equipment, they have limited application and can be dangerous if not used appropriately and/or without a spotter. Free weights are generally only useful in developing and exercising the upper body.
Lower body exercise has many medically important benefits including lower body weight, decreased risk of diseases such as diabetes, heart disease, and some cancers, lower body fat, improved physical appearance, reduced instances of depression, reduced symptoms of menopause, improved bladder control, reduced risk of injury, improved cholesterol levels, more positive self-esteem, better sleeping patterns, more energy & stamina, and many others. It is not a matter of debate that lower body workouts exercising the largest muscles in the body, aerobically stressing the cardiovascular system, and testing balance and coordination contribute greatly to physical and mental well-being.
For cardiovascular, calorie-burning, and lower-body workouts, well known devices include the stationary bicycle, the treadmill, the ski-machine, the stair-climber (e.g., Reissued U.S. Pat. No. Re. 34,959, issued May 30, 1995 to Potts), the elliptical machine, and many other similar devices. These devices are effective, but are expensive and take up a great deal of floor space; they are not very convenient. Because some of these devices such as the treadmill and the stair-climber cannot provide a low-impact workout, they can exacerbate joint and spine problems, and be painful to those sensitive to high impact workouts.
Known devices include exercise trampolines, ones that are about 3 feet (1 meter) in diameter and sit 8 to 10 inches (20–25 cm) off the floor, are inexpensive and can provide a relatively good low-impact lower-body workout, but they are too soft and result in too much bounce and not enough resistance. Furthermore, they take up a large amount of floor space and can be difficult to store when not in use, e.g., they generally will not fit into a closet.
In recognition that there exists a need for a simple, compact, low-impact lower-body exercise device, a number of patents have issued disclosing devices attempting to fill this need.
For example, U.S. Pat. No. 4,279,415, issued Jul. 21, 1981 to Katz, discloses a treadle exercise device comprising a pair of hinged pedals (treadles) biased upwardly by a pair of springs and blown or cellular polyurethane foam. Like many spring-biased treadle devices, the hinge of the Katz device is located behind the foot. This causes the user to either stand on his or her toes when stepping down on the treadle which can excessively strain the ankle, or overstretch the ankle (Achilles) tendon. Similar devices include those disclosed in U.S. Pat. No. 3,814,420, issued Jun. 4, 1974 to Encke; U.S. Pat. No. 3,638,940, issued Feb. 1, 1972 to Mehaulic; U.S. Pat. No. 3,628,791, issued Dec. 21, 1971 to Garcia; and U.S. Pat. No. 3,295,847, issued Jan. 3, 1967 to Matt, Sr.
Another type of device, shown by U.S. Pat. No. 4,645,197, issued Feb. 24, 1987 to McFee, describes an exercise device having a biased platform hinged at a position in front of the foot. The platform is adjusted so that the springs provide just sufficient energy to maintain the user at about mid-position when quiescent. The springs are pre-stressed and provide nearly constant force through the full range of motion of the platform. A shock absorber connected to the platform dissipates energy. In use, the overall action of the body is described as “not unlike swimming doing the breast stroke with a porpoise kick” (McFee, col. 6, lines 57–59). This device takes up a great deal of floor space, is complicated to set up and use, and is not easy to store.
U.S. Pat. No. 6,132,338, issued Oct. 17, 2000 to Shifferaw and U.S. Pat. No. 4,200,282, issued Apr. 29, 1980 to Agyagos, and U.K. Patent Specification U.S. Pat. No. 1,348,531, published Mar. 20, 1974 for Wheeler each show variations on a “bounce board” which include a spring biased or flexible platform for exercise or fun. The U.S. patent to Shifferaw may mar the floor or damage carpeting due to movement of the feet when the board is flexed. A danger exists with the Shifferaw and Wheeler devices that they may jump or move during use. The Agyagos device's platform has a very restricted range of movement and is hinged at one end very close to the heel which requires user to therefore stand and jump on his or her toes.
U.S. Pat. No. 3,929,329, issued Dec. 30, 1975 to Rivera discloses spring supported ski-boot bindings for testing out the feel of a pair of ski boots. This device is not designed to exercise the individual and relies on the stiffness of the ski boots to prevent it from unwanted tilting and wobbling. It is not practical for daily workouts.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed. Thus, an exercise device for lower body solving the aforementioned problems is desired.